Most of it, usually — but not always all of it, and anyone promising otherwise on an old stain is overselling. Oil soaks into concrete rather than sitting on it, which makes this the most expectation-sensitive part of concrete cleaning and stain treatment.
Why oil is different from dirt
Concrete is porous, and petroleum products are excellent at penetrating pores. A fresh drip sits mostly at the surface; a stain that has been recharged weekly by a parked car for two years has soaked deep into the slab.
Water-based cleaning does not touch it — oil and water famously decline to cooperate. Pressure alone actually spreads a fresh stain rather than removing it.
What treatment actually does
A degreaser breaks the oil’s bond with the concrete and emulsifies it so it can rinse. Dwell time matters more than product: the chemistry needs minutes to work into the pores, not seconds. Hot water helps; agitation helps; a second application on old stains is routine.
Fresh stains often disappear entirely. Old, deep stains lighten dramatically — commonly to a faint shadow visible only when you look for it — but the oil that has migrated deepest is beyond the reach of any surface treatment. That is the honest ceiling.
The order of operations that works
Degrease the stain first, then clean the whole slab uniformly with a surface cleaner so the treated area does not stand out as a clean patch on a grey slab. Then, if you want the result to last, seal — a sealed slab keeps the next drip on the surface where a rag can catch it.
For active drip spots under a daily-parked car, a drip tray costs almost nothing and saves the slab.
Photograph the stain and tell us roughly how old it is — we will give you an honest expectation before we quote. Read more about concrete cleaning and stain treatment →